Littelfuse 0672007.DRT4P Fuse - Equivalent & Substitute Parts

Part Overview

The Littelfuse 0672007.DRT4P is a 7 A, 250 V AC/DC fast-blow glass cartridge fuse with axial through-hole mounting. This component is classified as obsolete, making identification of suitable substitute parts essential for ongoing system maintenance and new design implementations. The glass cartridge construction provides visual indication of fuse status and is widely used in industrial and consumer electronics applications requiring reliable overcurrent protection.

Substiute Parts

0672007.DRT4P

Littelfuse Inc.In Stock: 7900672007.DRT4P Datasheet

Current PartRFQ

0874007.MRET1P

Littelfuse Inc.In Stock: 10810874007.MRET1P Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 0672007.DRT4P is determined by strict equivalence across the following critical parameters:

• Current Rating: 7 A (exact match required)
• Voltage Rating (AC): 250 V (exact match required)
• Response Time: Fast Blow (exact match required)
• Mounting Type: Through Hole (exact match required)
• Breaking Capacity @ Rated Voltage: 50 A (exact match required)
• Package / Case: Cartridge, Non-Standard (Axial) (exact match required)

The primary difference between the main part and its substitute lies in the cartridge material construction: the 0672007.DRT4P uses glass, while the substitute 0874007.MRET1P uses ceramic. Both materials satisfy the electrical and mechanical requirements for this application category. Physical dimensions vary slightly between the two designs, with the ceramic variant measuring 0.142" Dia x 0.394" L (3.60mm x 10.00mm) compared to the glass variant's 0.154" Dia x 0.433" L (3.90mm x 11.00mm).

Parameter Comparison

Engineering Selection Recommendations

The 0874007.MRET1P ceramic cartridge fuse is the manufacturer-recommended substitute for the obsolete 0672007.DRT4P glass cartridge fuse. Both components maintain identical electrical specifications for current rating, voltage rating, response time, and breaking capacity. The ceramic variant is currently in active production status, ensuring long-term availability and supply chain continuity.

The ceramic construction of the 0874007.MRET1P provides an operating temperature range of -55°C to 125°C, whereas the original glass variant does not specify an operating temperature range. The ceramic variant also carries cULus certification, which supersedes the CSA and UL certifications of the glass variant. Both parts are ROHS3 compliant and REACH unaffected.

Physical dimensions differ slightly between the two designs. The ceramic variant is marginally smaller in diameter (0.142" vs. 0.154") and length (0.394" vs. 0.433"). These dimensional differences must be evaluated against specific mechanical constraints within the target application, particularly regarding mounting hole spacing and clearance requirements in existing circuit board layouts or fuse holder designs.

The DC cold resistance of the ceramic variant (0.0099 Ohms) is lower than the glass variant (0.0111 Ohms), representing a 10.8% reduction in resistance. The melting I²t value of the ceramic variant (36.9) is higher than the glass variant (25.8), indicating a 43% increase in thermal energy capacity.

Frequently Asked Questions (FAQ)

Q: Can the 0874007.MRET1P ceramic fuse directly replace the 0672007.DRT4P glass fuse?

A: Yes, the 0874007.MRET1P is the manufacturer-recommended substitute. Both components share identical current rating (7 A), voltage rating (250 V AC), response time (fast blow), mounting type (through hole), and breaking capacity (50 A). The primary difference is cartridge material construction and slight dimensional variations.

Q: What are the dimensional differences between these two fuses?

A: The glass variant (0672007.DRT4P) measures 0.154" diameter x 0.433" length (3.90mm x 11.00mm). The ceramic variant (0874007.MRET1P) measures 0.142" diameter x 0.394" length (3.60mm x 10.00mm). The ceramic variant is approximately 0.012" smaller in diameter and 0.039" shorter in length. Verify that these dimensional differences are compatible with your specific fuse holder or mounting configuration.

Q: What is the difference between glass and ceramic cartridge fuses?

A: Glass cartridge fuses provide visual indication of fuse status through the transparent housing. Ceramic cartridge fuses offer enhanced thermal performance and typically provide a wider operating temperature range. Both types function identically from an electrical protection standpoint when specifications are matched.

Q: Are there any compliance or certification differences?

A: The glass variant carries CSA and UL certifications. The ceramic variant carries cULus certification, which represents a combined certification standard. Both variants are ROHS3 compliant and REACH unaffected.

Q: What is the significance of the melting I²t difference?

A: The ceramic variant has a melting I²t of 36.9 compared to the glass variant's 25.8. This indicates the ceramic variant requires greater thermal energy to melt the fuse element. This difference is within the acceptable range for fast-blow fuses at the 7 A rating and does not affect substitution compatibility.

Q: Is the lower DC cold resistance of the ceramic variant significant?

A: The ceramic variant's DC cold resistance (0.0099 Ohms) is 10.8% lower than the glass variant (0.0111 Ohms). This minimal difference has negligible impact on circuit performance and does not affect substitution compatibility.

Q: Why is the original glass fuse marked as obsolete?

A: The 0672007.DRT4P is classified as obsolete by the manufacturer. The 0874007.MRET1P ceramic variant is the active production replacement, ensuring continued availability and support for this fuse specification.